Beijing: China has conducted live fire drills along its borders with North Korea, marking the first military activity in the area since Pyongyang stepped up threats to attack South Korea and the US.

Tanks and armoured vehicles from a Shenyang military unit took part in the drills on the Chinese side, Hong Kong-based South China Morning Post reported.

The development comes in the wake of China toughening its stand on North Korea with Chinese President Xi Jinping saying that "nobody should be allowed to throw a region and even the whole world into chaos for selfish gains."

North Korea has threatened nuclear strikes against the US and South Korea, with reports that it has positioned two mobile missile launchers on the country's east coast.

On Thursday, about 50 North Korean soldiers also engaged in parachute drills for about two hours near Dandong in Liaoning province.

Meanwhile, the Chinese Defence Ministry denied foreign media reports that there has been a build up by PLA on the border with North Korea.

"The reports are not true. China is paying close attention to the development of the current situation on the Korean Peninsula and has always been committed to safeguarding peace and stability in Northeast Asia," a ministry spokesman said.